The Peritoneum: Anatomy, Pathologic Findings, and Patterns of Disease Spread

Disease spread in the abdomen and pelvis generally occurs in a predictable pattern in relation to anatomic landmarks and fascial planes. Anatomically, the abdominopelvic cavity is subdivided into several smaller spaces or compartments by key ligaments and fascial planes. The abdominal cavity has been traditionally divided into peritoneal, retroperitoneal, and pelvic extraperitoneal spaces. Recently, more clinically relevant classifications have evolved. Many pathologic conditions affect the abdominal cavity, including traumatic, inflammatory, infectious, and neoplastic processes. These abnormalities can extend beyond their sites of origin through various pathways. Identifying the origin of a disease process is the first step in formulating a differential diagnosis and ultimately reaching a final diagnosis. Pathologic conditions differ in terms of pathways of disease spread. For example, simple fluid tracks along fascial planes, respecting anatomic boundaries, while fluid from acute necrotizing pancreatitis can destroy fascial planes, resulting in transfascial spread without regard for anatomic landmarks. Furthermore, neoplastic processes can spread through multiple pathways, with a propensity for spread to noncontiguous sites. When the origin of a disease process is not readily apparent, recognizing the spread pattern can allow the radiologist to work backward and ultimately arrive at the site or source of pathogenesis. As such, a cohesive understanding of the peritoneal anatomy, the typical organ or site of origin for a disease process, and the corresponding pattern of disease spread is critical not only for initial diagnosis but also for establishing a road map for staging, anticipating further disease spread, guiding search patterns and report checklists, determining prognosis, and tailoring appropriate follow-up imaging studies. ©RSNA, 2024 Supplemental material is available for this article.

Clinical and radiological risk factors for poor outcomes in patients with spontaneous muscle hematomas

PURPOSE

Spontaneous muscle hematomas (SMH) are frequently seen in the Emergency Department (ED), particularly as a complication of anticoagulation treatments. To date, there are no standard guidelines for the management of this condition in the ED. This work aims to identify clinical-radiological parameters of SMH at risk of poor outcomes.

METHOD

This is a retrospective, observational cohort study conducted in an urban teaching hospital from 2016 to 2019. A multivariate logistic regression analysis was performed to identify parameters independently associated with an adverse outcome defined as the need for treatment (blood products, TAE, surgery) or hospitalization. The parameters analyzed were hematoma size, anticoagulation therapy, age, and the Charlson Comorbidity Index (CCI). ROC analysis was performed to identify the best cut-off hematoma size value to predict poor outcomes.

RESULTS

Our study enrolled 231 patients aged between 18 and 96 years, with a mean age of 67 years. In our population, 125 patients (54.1 % %) were on anticoagulant therapy. Multivariate analysis showed that an SMH diameter > 5.5 cm was independently associated with poor outcome ((odds Ratio [95 % CI] 4,009 [1,786-9,001], p 0.001). Among clinical parameters, only advanced age was proved to be an independent predictor of adverse outcomes (odds Ratio [95 % CI] 1,035 [1,003-1,069], p = 0.033) CONCLUSIONS: Our data suggest that an SMH diameter greater than 5.5 cm on a CT scan and advanced age are predictors of poor outcomes. Surprisingly, anticoagulant therapy seems to play a minor role in the outcome of SMHs.

Etiology, morphology, and outcomes of adrenal calcifications in 540 adult patients-a retrospective single-center study

Sparse data are available on the etiology, morphology, clinical presentation, and outcomes of adrenal calcification. In this single-center retrospective study of 540 consecutive patients (median age 65 years, 45% women) with adrenal calcification on computed tomography (December 2017 to January 2021), most were discovered incidentally (472, 87%). The commonest etiology was idiopathic (389, 72%), followed by the adrenal tumor (113, 21%), hemorrhage (29, 5%), and infiltrative disease (7, 1%). Calcified adrenal tumors were predominantly benign (92, 81%) and primarily adenomas (63, 69%), whereas the most common calcified adrenal malignancy (16, 18%) was metastasis (12, 67%). Calcification (unilateral 94%, bilateral 6%) morphology varied from punctate (313, 58%) to coarse (165, 30%), linear/curvilinear (46, 9%), and rim-like (16, 3%). In summary, adrenal calcifications are usually incidentally discovered unilateral, punctate, or coarse lesions of unclear etiology. Most calcified adrenal tumors are benign and <20% malignant or pheochromocytomas.

Appendiceal Inversion Presenting as a Cecal Polypoid Mass on Screening Colonoscopy: A Case Report and Review of Available Diagnostic Adjuncts to Differentiate Benign From Malignant Colorectal Pathology

Appendiceal inversion is uncommon. It may be a benign finding or seen in association with malignant pathology. When detected, it masquerades as a cecal polyp which poses a diagnostic dilemma with malignancy in the differential. In this report, we highlight a case of a 51-year-old patient with an extensive surgical history as a newborn in the setting of omphalocele and intestinal malrotation, who was found to have a 4 cm cecal polypoid growth on screening colonoscopy. He underwent a cecectomy for tissue diagnosis. Ultimately, the polyp was found to be an inverted appendix without evidence of malignancy. Currently, suspicious colorectal lesions which cannot be removed by polypectomy are primarily addressed with surgical excision. We reviewed the literature for available diagnostic adjuncts to better differentiate benign from malignant colorectal pathology. The application of advanced imaging and molecular technology will allow for improved diagnostic accuracy and subsequent operative planning.

Three-dimensional dispersion entropy for uterine fibroid texture quantification and post-embolization evaluation

BACKGROUND AND OBJECTIVE

Uterine fibroids are benign tumors that could lead to symptoms complicating a patient's daily life. Those fibroids can be treated using uterine fibroid embolization (UFE), an effective non-surgical procedure. However, objectively quantifying the benefits of such a procedure, and the patient's quality of life, is rather challenging.

METHODS

With a novel multiscale three-dimensional (3D) entropy-based texture analysis, the multiscale 3D dispersion entropy (MDispEn_3D), this work aims to objectively quantify the evolution -  after UFE  -  of patients' health in terms of quality of life, symptoms severity, and sexual function. For this purpose, clinical data and magnetic resonance imaging (MRI) scans of fibroids are analyzed before UFE (D0), ten days after (D10), and six months after (M6).

RESULTS

An inverse correlation is observed between MDispEn_3D entropy values and both size and volume of fibroids. An inverse correlation is also observed between MDispEn_3D at M6 and the scores of symptoms severity. Moreover, the patient age is found to be related to the relative difference of DispEn_3D and MDispEn_3D values, between D0 and M6, translating into an increasing entropy value. Furthermore, we show that history of fibroma plays a role in determining the obtained DispEn_3D values at D0. Finally, we observe that the lower MDispEn_3D values at D0, the larger the size of the fibroid at M6.

CONCLUSIONS

The proposed MDispEn_3D method - by quantifying fibroid texture - could assist the medical doctors in the prognosis of uterine fibroids and the patients' quality of life assessment post-UFE. It could therefore favor the choice of this treatment compared to other more invasive surgical treatments.

The CT scout view: complementary value added to abdominal CT interpretation

Computed tomography (CT) scout images, also known as CT localizer radiographs, topograms, or scanograms, are an important, albeit often overlooked part of the CT examination. Scout images may contain important findings outside of the scanned field of view on CT examinations of the abdomen and pelvis, such as unsuspected lung cancer at the lung bases. Alternatively, scout images can provide complementary information to findings within the scanned field of view, such as characterization of retained surgical foreign bodies. Assessment of scout images adds value and provides a complementary "opportunistic" review for interpretation of abdominopelvic CT examinations. Scout image review is a useful modern application of conventional abdominal radiograph interpretation that can help establish a diagnosis or narrow a differential diagnosis. This review discusses the primary purpose and intent of the CT scout images, addresses standard of care and bias related to scout image review, and presents a general systematic approach to assessing scout images with multiple illustrative examples, including potential pitfalls in interpreting scout images.

Calcified pseudocyst: an uncommon presentation of chronic pancreatitis

Pseudocysts are localised fluid collections, usually developing as a complication of acute or chronic pancreatitis. Pancreatic ductal or parenchymal calcifications are commonly seen in routine radiological imaging, but calcification of pseudocyst is extremely rare. Calcified pseudocysts have been reported in literature as case reports, but a calcified pseudocyst in the lesser sac, without underlying pancreatic calcification, has not been reported. We report a case of a pancreatic pseudocyst with a calcified wall, requiring surgical excision and histological examination confirming the diagnosis.

Focal hepatic intrinsically hyperattenuating lesions at unenhanced CT: Not always calcifications

Due to the growing use of CT, there has been an increase in the frequency of detecting focal liver lesions. Intrinsically hyperattenuating hepatic lesions or pseudolesions are not uncommon at unenhanced CT. Hyperattenuating hepatic lesions can be divided into non-calcified and calcified. Causes of intrinsic hyperattenuation include hemorrhage, thrombosis, and calcifications. Focal liver lesions can show hyperattenuation on unenhanced CT in case of severe liver steatosis. Recognition of etiologies associated with hyperattenuation on unenhanced CT can help the radiologist in characterizing focal liver lesions and pseudolesions. In this paper, we describe the spectrum of intrinsically hyperattenuating focal liver lesions and pseudolesions at unenhanced CT.

Feasibility study of oxidized hyaluronic acid cross-linking acellular bovine pericardium with potential application for abdominal wall repair

Bovine pericardium(BP)is one of the biological membranes with extensive application in tissue engineering. To fully investigate the potential clinical applications of this natural biological material, a suitable cross-linking reagent is hopefully adopted for modification. Glutaraldehyde (GA) is a clinically most common synthetic cross-linking reagent. In the study, oxidized hyaluronic acid (AHA) was developed to substitute GA to fix acellular bovine pericardium (ABP) for lower cytotoxicity, aiming to evaluate the feasibility of AHA as a cross-linking reagent and develop AHA-fixed ABP as a biological patch for abdominal wall repair. The AHA with the feeding ratio (1.8:1.0) has an appropriate molecular weight and oxidation degree, almost no cytotoxicity and good cross-linking effect. The critical cross-linking characteristics and cytocompatibility of AHA-fixed ABP were also investigated. The results demonstrated that 2.0% AHA-fixed ABP had the most suitable mechanical properties, thermal stability, resistance to enzymatic degradation and hydrophilicity. Moreover, 2.0% AHA-fixed samples exhibited an excellent cytocompatibility with human peritoneal mesothelial cells (HPMC) and low antigenicity. It also showed a prominent anti-calcification ability required for abdominal wall repair. Our data provided experimental basis for future research on AHA as a new cross-linking reagent and AHA-fixed ABP for abdominal wall repair.

Imaging Manifestations of Genitourinary Tuberculosis

The genitourinary region is one of the most common sites of extrapulmonary tuberculosis (TB) involvement. The imaging features of genitourinary TB are protean and can mimic other entities, including malignancy, and pose a diagnostic dilemma. Hematogenous seeding and lymphatic spread of mycobacteria from pulmonary, tonsillar, and nodal TB are implicated in the pathogenesis of genitourinary TB. In addition, contiguous extension from the urinary tract and sexual transmission are described as sources of genital TB. Genitourinary TB can be indolent and results in nonspecific signs and symptoms; thus, imaging has a vital role in the working diagnosis for these cases. Classic uroradiologic signs of genitourinary TB are primarily described from the era of intravenous urography and conventional radiography. Now, CT, CT urography, MRI, and US are used in the diagnosis and management. Familiarity with the imaging features of genitourinary TB may help guide the diagnosis and, in turn, lead to timely management. US has a vital role in the evaluation of scrotal and female genital TB. MRI offers superior soft-tissue contrast resolution and excellent depiction of anatomic detail. The various imaging manifestations of genitourinary TB are highlighted. ^©RSNA, 2021.